Medical equipment and industrial robots are often required to move with high precision. Therefore, it is imperative to develop compact, lightweight, and flexible actuator devices. For example, many actuator devices have been developed, which use a flexible member formed by bonding two sheets of electrostrictive material together.
Recently, to realize actuator devices of lighter weight, actuator devices using films of electrostrictive material have been developed. Films made of electrostrictive material are stacked in layers to form a multilayer body, which functions as an actuator device by T-shaped connection of electrodes using conductive paste or the like, the electrodes being exposed by cutting to a cross section of the multilayer body.
To enhance the strength of an actuator device, for example, as in a film capacitor disclosed in Japanese Unexamined Patent Application Publication No. 09-232185, films made of electrostrictive material are stacked to form a multilayer body, which is rolled and used as a cylindrical actuator device. In Japanese Unexamined Patent Application Publication No. 09-232185, a metal, such as Al, Cu, or Au, is used in electrodes. Outer electrodes are formed by thermal spraying of metal onto both end portions of the cylindrical actuator device.